Animals sensitized to allergens change their feeding behavior and avoid drinking the otherwise preferred sweetened solutions containing the allergens. This phenomenon, known as food aversion, appears to be mediated by allergen-specific IgE antibodies. Here we investigated food aversion in BALB/c and C57BL/6 mice, which differ in their allergic responses to the allergen ovalbumin as well as in their preference for sweet taste. BALB/c mice present higher levels of IgE and a natural lower preference for sweet flavors when compared to C57BL/6 mice. Specifically, we studied a conflicting situation in which animals simultaneously experienced the aversive contact with the allergen and the attractive sweet taste of increasing concentrations of sucrose. We found that BALB/c mice were more prone to develop food aversion than C57BL/6 mice and that this aversive behavior could be abolished in both strains by increasing the palatability of the solution containing the allergen. In both strains food aversion was positively correlated with the levels of allergen-specific IgE antibodies and inversely correlated with their preference for sucrose sweetened solutions

Animals sensitized to allergens change their feeding behavior and avoid drinking the otherwise preferred sweetened solutions containing the allergens. This phenomenon, known as food aversion, appears to be mediated by allergen-specific IgE antibodies. Here we investigated food aversion in BALB/c and C57BL/6 mice, which differ in their allergic responses to the allergen ovalbumin as well as in their preference for sweet taste. BALB/c mice present higher levels of IgE and a natural lower preference for sweet flavors when compared to C57BL/6 mice. Specifically, we studied a conflicting situation in which animals simultaneously experienced the aversive contact with the allergen and the attractive sweet taste of increasing concentrations of sucrose. We found that BALB/c mice were more prone to develop food aversion than C57BL/6 mice and that this aversive behavior could be abolished in both strains by increasing the palatability of the solution containing the allergen. In both strains food aversion was positively correlated with the levels of allergen-specific IgE antibodies and inversely correlated with their preference for sucrose sweetened solutions. (C) 2009 Elsevier Inc. All rights reserved.

Background: Mice allergic to ovalbumin (OVA) avoid drinking a solution containing this antigen. This was interpreted as related to IgE-dependent mast cell degranulation and sensory C fiber activation. Methods: We employed pharmacological manipulation to further investigate the mediators involved in immune-induced food aversion. Results: While nonimmunized rats preferred a sweetened OVA solution, immunized rats avoided it. We also employed a paradigm in which rats are conditioned to drink water for two 10-min sessions a day. Tolerant rats presented lower IgE titers, and this manipulation abrogated food aversion. Dexamethasone (1.0 mg/kg) prevented the aversion of OVA-immunized rats to the antigen-containing solution. Combined blockade of H(1) and 5-hydroxytryptamine (5-HT)(2) receptors by promethazine (3.0 mg/kg) plus methysergide (5.0 mg/kg) was unable to alter food aversion. Blockade of 5-HT(3) receptors by ondansetron (1.0 mg/kg) caused a twofold increase in the ingestion of the sweetened OVA solution by immunized rats, suggesting the involvement of 5-HT(3) receptors in food aversion. Finally, we showed that dexamethasone or promethazine plus methysergide, but not ondansetron, effectively prevented the IgE-dependent mast-cell-degranulation-induced increase in vascular permeability in rats. Conclusion: We suggest that regardless of whether or not they cause edema...

Modern literature departs from time-separable constant relative risk aversion preferences to explain asset pricing facts. This deviation typically implies that wealth shocks generate transitory variations in agents’ relative risk aversion and, possibly, portfolio re-allocations over time. I empirically analyze this relationship using U.S. macroeconomic data and and evidence for time-variation in portfolio shares that is consistent with counter-cyclical risk aversion. These results suggest, therefore, that wealth-dependent, habit-formation or loss and disappointment aversion utility functions are a good description of preferences. Controlling for observed versus expected asset returns, I also show that: (i) wealth effects are significant (although temporary) and there is no evidence of inertia contrary to Brunnermeier and Nagel (2006); and (ii) the consumption-wealth ratio (Lettau and Ludvigson, 2001), the labor income risk (Julliard, 2004) and the labor income-consumption ratio (Santos and Veronesi, 2006) partially explain changes in the risky asset share.; Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/12985/2003.

The cannabinoid system is known to interact with a variety of neuromodulators in the central nervous system and impacts diverse behaviors. Previous studies have demonstrated that limbic norepinephrine is a
critical determinant in the behavioral expression of cannabinoid-induced aversion. The present study was carried out to define the adrenergic receptor subtype involved in mediating cannabinoid-induced behavioral responses. An acute microinjection of the 1-adrenergic receptor blocker, betaxolol, directly into the
nucleus accumbens (Acb), was able to prevent WIN 55,212-2-induced aversion, but not lithium-induced aversion, as measured in a place conditioning paradigm. These results suggest that noradrenergic transmission in the Acb is important for cannabinoid-induced aversion and that beta-adrenergic antagonists may be effective in counteracting negative side effects of cannabinoid-based agents.; This work was supported by PHS grant DA 020129. Ana Franky Carvalho was supported by the Portuguese Foundation for Science and Technology (SFRH/BD/33236/2007)

RATIONALE:
The cannabinoid system has risen to the forefront in the development of novel treatments for a number of pathophysiological processes. However, significant side effects have been observed in clinical trials raising concerns regarding the potential clinical utility of cannabinoid-based agents. Understanding the neural circuits and neurochemical substrates impacted by cannabinoids will provide a better means of gaging their actions within the central nervous system that may contribute to the expression of unwanted side effects.
OBJECTIVES:
In the present study, we investigated whether norepinephrine (NE) in the limbic forebrain is a critical determinant of cannabinoid receptor agonist-induced aversion and anxiety in rats.
METHODS:
An immunotoxin lesion approach was combined with behavioral analysis using a place conditioning paradigm and the elevated zero maze.
RESULTS:
Our results show that the non-selective CB1/CB2 receptor agonist, WIN 55,212-2, produced a significant place aversion in rats. Further, NE in the nucleus accumbens was critical for WIN 55,212-2-induced aversion but did not affect anxiety-like behaviors. Depletion of NE from the bed nucleus of the stria terminalis was ineffective in altering WIN 55,212-2-induced aversion and anxiety.
CONCLUSIONS:
These results indicate that limbic...

The aim of this study was to determine whether goats could be averted from consuming Mascagnia rigida, a toxic plant found in the semiarid region of northeastern Brazil. Fourteen male goats not previously familiarized to M. rigida were randomly allocated to two treatment groups: control (treated with 5.5mL water orally by a drenching gun) and lithium group (treated with 100mg LiCl/kg body weight orally by a drenching gun). For conditioning, goats were allowed to feed on M. rigida leaves for 15 min, followed by LiCl or water administration. The time spent on eating M. rigida leaves was measured. The conditioning was repeated daily until the LiCl-treated goats stopped eating M. rigida. On the 10th, 17th, and 24th day after conditioning, extinction trials of the M. rigida aversion were performed in goats by using single-choice tests. There was no difference between the two treatment groups with respect to the consumption of M. rigida on the first day of aversion conditioning, however, controls ingested increasing amounts of the plant on consecutive conditioning days. On the second day, five out of the seven goats in the lithium group did not eat the leaves, but on the third day, all the goats in the lithium group did not ingest M. rigida. This aversion persisted throughout all evaluated days. This indicates that goats can be easily conditioned by using lithium chloride to avoid eating M. rigida temporarily.

Baccharis coridifolia is a plant that induces strong conditioned food aversion in ruminants. This research aimed to induce a conditioned food aversion to Ipomoea carnea var. fistulosa in goats, using B. coridifolia as an aversive agent, and to compare the aversion induced by this plant with the aversion induced by lithium chloride (LiCl). Thirteen goats were allotted into two groups: Group 1 with six goats was averted with 175mg/kg of body weight of LiCl and Group 2 with seven goats was averted with 0,25g/kg of bw of dried B. coridifolia. All goats were averted on day 1 after the ingestion of I. carnea. The aversion procedure with LiCl or B. coridifolia in goats from Groups 1 and 2, respectively, was repeated in those goats that again consumed the plant during tests on days 2, 3, and 7. The goats of both groups were challenged in pens on 23 and 38 days after the last day of aversion and challenged in the pasture on days 11, 15, 18, 20, 22, 25, 27 and 29 after the last day of aversion. After this period goats were challenged every 15 days on pasture until the 330º day after the last day of aversion (7th day). Two goats from Group 1 ingested I. carnea on the first day of the pasture challenge, 4 days after the last day of aversive conditioning in the pen. In addition...

Palicourea aeneofusca contains sodium monofluoroacetate, which causes sudden death in ruminants when administered at doses of approximately 0.6g kg-1 of body weight (g kg-1). In this experiment two groups of 6 goats were used to determine the possibility to induce conditioned food aversion to P. aeneofusca. In group 1, 0.35g kg-1 of green leaves of the plant were given to six goats on days 1, 5, 10, 20, 30, 60, and 90 of the experiment. On the first day, all of the goats ingested the full amount of the plant and were treated immediately with 175mg kg-1 of lithium chloride (LiCl) through a ruminal tube. On day 5, only two goats ingested the plant, and they were treated with the same dose of LiCl. On days 10, 20, 30, 60, and 90, none of the goats ingested the plant. For another group of 6 goats, the leaves were given on days 1, 10, 20, 30, 60, and 90. All of the goats ingested the leaves on day 1 and received 1mL kg-1 body weight of water through a ruminal tube. All of these goats ingested the plant on days 10, 20, 30, 60, and 90. These results demonstrate that it is possible to induce conditioned food aversion to P. aeneofusca that persists for at least 90 days. Further experiments should be performed to determine the duration of the aversion and to induce aversion to other Palicourea species...

In this paper :
a) the consumer’s problem is studied over two periods, the second one involving S states, and the consumer being endowed with S+1 incomes and having access to N financial assets;
b) the consumer is then representable by a continuously differentiable system of demands, commodity demands, asset demands and desirabilities of incomes (the S+1 Lagrange multiplier of the S+1 constraints);
c) the multipliers can be transformed into subjective Arrow prices;
d) the effects of the various incomes on these Arrow prices decompose into a compensation effect (an Antonelli matrix) and a wealth effect;
e) the Antonelli matrix has rank S-N, the dimension of incompleteness, if the consumer can financially adjust himself when facing income shocks;
f) the matrix has rank S, if not;
g) in the first case, the matrix represents a residual aversion; in the second case, a fundamental aversion; the difference between them is an aversion to illiquidity; this last relation corresponds to the Drèze-Modigliani decomposition (1972);
h) the fundamental aversion decomposes also into an aversion to impatience and a risk aversion;
i) the above decompositions span a third decomposition; if there exists a sure asset (to be defined, the usual definition being too specific)...

We use household survey data to construct a direct measure of absolute risk aversion based on the maximum price a consumer is willing to pay for a risky security. We relate this measure to consumers.endowments and attributes and to measures of background risk and liquidity constraints. We .nd that risk aversion is a decreasing function of the endowment. thus rejecting CARA preferences. We estimate the elasticity of risk aversion to consumption at about 0.7, below the unitary value predicted by CRRA utility. We also .nd that households. attributes are of little help in predicting their degree of risk aversion, which is characterized by massive unexplained heterogeneity. We show that the consumer.s environment affects risk aversion. Individuals who are more likely to face income uncertainty or to become liquidity constrained exhibit a higher degree of absolute risk aversion, consistent with recent theories of attitudes toward risk in the presence of uninsurable risks

In standard contract-theoretic models, the underlying assumption is that an agent is
purely selfish, and his objective is to maximize his own payoff. A large amount of
empirical evidence has pointed out that many individuals are also motivated by other
psychological considerations, such as fairness concerns and reciprocity. Theorists
have been engaged in finding more realistic assumptions that are consistent with
the ways in which economic agents behave in real life. Among the existing theories,
the theory of inequity aversion developed by Fehr and Schmidt [35] has attracted
enormous attention. It soon became a useful tool in behavioral contract theory, which
capitalizes on the power of social preferences theories to enhance understanding of
real-world contracting phenomena. The present thesis aims at contributing to the
behavioral contract literature by investigating how inequality aversion preferences
impact on the optimal contract design in a financial contracting environment and the
agent's incentive in a career concerns experiment.
Chapter 2 reviews some of the recent theoretical contributions to the development
of the theories of reciprocity and fairness. Emphasis is placed on sketching the theories, demonstrating their abilities to explain experimental regularities and pointing out some potential problems that are inherent in the existing theories. In addition...

Ipomoea carnea is a toxic plant often ingested by livestock in Brazil. Three experiments were conducted to determine if conditioned food aversion was effective in reducing goats' consumption of I. carnea. In the first experiment, 10 mildly intoxicated goats that had been eating I. carnea were averted using LiCl (175 to 200mg kg-1 body weight). These intoxicated goats did not develop an aversion to I. carnea, demonstrating that the technique is not effective in goats that are already accustomed to consuming the plant. In the second experiment, 14 naïve goats were placed in a pasture with I. carnea, and averted after they ingested the plant. In this group the aversion persisted until the end of the experiment, 2 years and 8 months after the initial aversion. In another experiment, 20 goats were placed in a pasture with I. carnea, and after consuming the plant were averted with LiCl. The averted goats were transferred to Marajo Island and periodically observed over a 2 year period at 2-3 month intervals to determine if they were still averted. The averted goats did not ingest the plant while grazing in the pasture, whereas in 6 neighboring goat farms the prevalence of intoxication from I. carnea poisoning was estimated to be about 40%. These results demonstrated the efficacy of conditioned food aversion to avoid ingestion of I. carnea in formerly naïve goats that had only recently begun to ingest the plant.

Trabajo publicado como artículo en Social Choice and Welfare 28(1): 89-110 (2007).-- http://dx.doi.org/10.1007/s00355-006-0151-x; In this paper we propose the infimum of the Arrow-Pratt index of absolute risk aversion as a measure of global risk aversion of a utility function. We then show that, for any given arbitrary pair of distributions, there exists a threshold level of global risk aversion such that all increasing concave utility functions with at least as much global risk aversion would rank the two distributions in the same way. Furthermore, this threshold level is sharp in the sense that, for any lower level of global risk aversion, we can find two utility functions in this class yielding opposite preference relations for the two distributions.; Financial support from the Spanish Ministry of Science and Technology through grants SEC2000-0684 and SEC 2000-1326, and from the Generalitat of Catalonia through grant SGR2001-00162 is gratefully acknowledged.

Using self reported measures of life satisfaction and risk attitudes, we empirically test whether there is a relationship between individuals inequality and risk aversion. The empirical analysis uses the German SOEP household panel for the years 1997 to 2007 to conclude that the negative effect of inequality measured by the sample gini coefficient by year and federal state is larger for those individuals who report to be less willing to take risks. Nevertheless, the empirical results suggest that even though inequality and risk aversion are related, they are not the same thing. The paper shows that the relationship between risk attitudes and inequality aversion survives the inclusion of individual characteristics (i.e. income, education, and gender) that may be correlated with both risk attitudes and inequality aversion.

The risk premium is affected by loss aversion and probability distortions as well as utility curvature. We introduce two variants - the total risk premium relative to objective expected value, and the subjective risk premium relative to perceived expected value. Approximate solutions for each provide analogies to the Pratt-Arrow coefficient of risk aversion (showing how risk attitude depends on each behavioural component), and sufficient conditions for risk aversion. Earlier results of Levy and Levy (2002) which examined decision weights in isolation are revised and extended to show how the curvature and loss aversion conditions are affected by probabilitydistortions.

We investigated the hypothesis that feeding deterrence of common ringtail possums (Pseudocheirus peregrinus) and common brushtail possums (Trichosurus vulpecula) by Eucalyptus terpenes (in this case 1,8-cineole) is a result of a conditioned flavor aversion (CFA), due to the association of terpenes with postingestive effects of another group of Eucalyptus toxins, the diformylphloroglucinol compounds (DFPCs). Wild-caught common ringtail and common brushtail possums showed a dose-dependent reduction in food intake when 1,8-cineole was added to the diet. However, after continued exposure over 12 days to increasing amounts of cineole in the diet, both species substantially increased their intakes of cineole relative to control animals. This indicated that the aversion to cineole was a conditioned response rather than a physiological limitation in their ability to detoxify terpenes. Subsequent exposure to a diet including both cineole and jensenone (a simple DFPC also found in Eucalyptus and considered to cause postingestive emesis) in corresponding amounts was able to recondition the dose-dependent aversion. Consequently, animals that had been given jensenone showed an aversion to cineole-rich diets that matched the behavior of animals in the control group. This supported our hypothesis that the effect of terpenes on feeding of these marsupial folivores on Eucalyptus is due to a CFA. Possums can cope with levels of terpenes in the diet that far exceed those occurring naturally. The role of terpenes in marsupial folivore-Eucalyptus interactions appears to be to act as a cue to levels of toxic DFPCs in the leaves...

This study has as its main goal to verify if gender, age and occupation have any influence at loss aversion level. The results taken are based in collected data through questionnaire applied to 516 professionals and students in the accounting area. The problems used are based on the questionnaire developed by Kahneman and Tversky in 1979. In Study I - Analysis of Students and Professionals x Gender, the goal was to verify if the gender has any influence in their loss aversion. In Study II - Analysis of Students and Professionals x Age, the goal was to be able to know if the age range has any influence in the loss aversion. In the so-called Study III - Students Analysis versus Professionals Analysis found that the occupation of the respondents influences the level of loss aversion. The results of three studies show evidence of influence of age, gender and occupation the level of loss aversion.; Este estudo tem por principal objetivo verificar se o gênero, a idade e a ocupação exercem influência no nível de aversão à perda. Os resultados obtidos baseiam-se em dados coletados por meio de questionários aplicados a 516 profissionais e estudantes da área contábil. Os problemas utilizados baseiam-se no questionário desenvolvido por Kahneman e Tversky em 1979. No Estudo I - Análise de Estudantes e Profissionais x Gênero...

INTRODUCTION: It is increasingly important to recognize the reward and aversion systems of the brain as a functional unit. A fundamental task of the mammalian brain is to assign an emotional/motivational valence to any stimuli by determining whether they are rewarding and should be approached or are aversive and should be avoided. Internal stimuli are also assigned an emotional/motivational valence in a similar fashion.OBJECTIVE: To understand the basic mechanisms and functions of the reward and aversion system of the brain.METHOD: A bibliographical search was conducted in the Pubmed database using different key words. Documents on relevant aspects of the topic were selected.RESULTS: In the ventral tegmental area, dopaminergic (VTA-DA) neurons play a role in reward-dependent behaviors. It is also known that the inhibition of the VTA-DA neurons by GABAergic neurons contributes to a reward prediction error calculation that promotes behaviors associated with aversion. The ventral dopaminergic mesolimbic system and the nucleus accumbens are activated during reward and inhibited during aversions. The amygdala is activated during aversive behavior.DISCUSSION AND CONCLUSION: The reward/aversion system is highly relevant for survival, which is most likely its primary function. It is involved in important pathologies such as addiction...